The immunologists at this institution have narrowed a broad program in Immunologic Aspects of Cancer to a coherent and concise theme of Immunologic Resistance to Cancer. This multifaceted approach toward a single goal encompasses the following broad sections with their collaborative projects: 1. Mechanisms of control of lymphoid tumor growth evaluating interaction of normal lymphoid cells as growth requirement of lymphoid tumors, suppressor cell induction by reticulum cell sarcoma, genetic control of resistance to murine plasmacytomas, immunosuppressive activity of mononuclear cells from plasmacytoma mice, and lymphocyte membrane components. 2. Transfer factor characterization by means of rabbit antibody and isoelectric focusing, in vivo assay of TFd in human to BALB/c mouse and mouse to mouse transfer of CMI, effects of murine TFd on growth of SV tumors in BALB/c mice, and effects of human TFd on growth of human melanoma in NU/NU mice. 3. Studies of cell-mediated immunity to solid tumors in human and in chicken models. 4. The monocyte-macrophage system in resistance to tumors - studies of human macrophages in long-term culture, comparison and properties of monocytes from normals and cancer patients, studies of human monocyte in vitro killing of tumor cells. 5. Role of antitumor immune complexes and complement in host defense in cancer patients.